Electric furnace.



J. W. EVANS.

ELEOTRIO FURNACE. APPLICATION FILED JULY 15, 1909. 960,862. Patented June 7, 1910.

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llllllllllllllll [JUL JOHN W. EVANS, OF BELLEVILLE, ONTARIO, CANADA.

ELECTRIC FURNACE.

Specification of Letters Patent.

Application filed July 15, 1909.

Patented June '7, 1910. Serial No. 507,680.

To all whom it may concern:

Be it known that 1, JOHN W. EvANs, a subject of the King of England, and resident of Belleville, in the Province of Ontario and Dominion of Canada, have invented certain new and useful Improvements in Electric Furnaces, of which the following is a specification.

The object of my invention is to provide an electric furnace capable of reducing ores and other materials to be melted, and has particular reference to the production of steel, malleable iron and pig iron direct from iron ore.

In carrying out my invention I provide a suitable furnace 'with opposed electrodes adapted to. produce the electric are above the material to be melted, and a pair of substantially ,vertically disposed electrodes adapted to be lowered more or less into said material to heat the same by the passage of the electric current through said material or the slag formed thereon, the arrangement of the electrodes being such that one of the substantially horizontally disposed electrodes and one of the substantially vertically disposed electrodes may be used on one side of the furnace to produce an arc, and the horizontal and vertical electrodes on the other side of the furnace may also produce an arc, whereby material at the side or sides of the furnace that may not have been sufiiciently heated or which may have become cooled may be heated at any desired time.

My invention further comprises the novel details of improvement and combinations of parts that will be more fully hereinafter set forth and then pointed out in the claims.

Reference is to be had to the accompanying drawings forming part hereof, wherein, Figure 1 is a vertical section of an electric furnace embodying my invention; Fig. 2 is a cross section thereof substantially on the line 2, 2, in Fig. 1, and Fig. 3 is a section onthe line 3, 3, in Fig. 1.

Similar numerals of reference indicate corresponding parts in the several views.

In the drawings the numeral 1 indicates a furnace which may be of any suitable construction and is preferably provided with an arched inner chamber into which the ores or other material to be treated mabe passed through a suitable hopper 2 s own provided with a plug or stopper 3 having a suitable vent 4 for gases, the outlet for slag being shown at 5 and the outlet for metal at 6. Said chamber is practically air tight to exclude the atmosphere during operation.

At 7 are substantially horizontally disposed electrodes shown passing through suitable openings in the side walls of the furnace and provided with suitable water jackets 8, with suitable insulation. Any suitable means may be provided for supporting and operating said electrodes. I have shown said electrodes connected with rods 9 passing through stuffing boxes 10 and having racks 9 engaged by pinions 11 carried by shafts 12 supported by brackets 13, whereby the electrodes may be operated. Said electrodes are located in such position as to produce the electric are above the level of the ore or other material in the furnace, so as to heat the same by reflect-ed heat from the arc.

At 15 are substantially Vertically disposed electrodes passing downwardly through the top of the furnace and at a suitable distance apart, whereby when said electrodes are pushed downwardly into the material in the chamber, and the electric current is passed through the same, such material will be melted in the well known manner. The electrodes 15 are shown located substantially in vertical alinement with the path or plane of the electrodes 7 in such position that an arc may be formed between the adjacent electrodes 7 and 15 at the sides of the furnace as desired when a pair of electrodes 7 and 15 are adjusted in pro-per position. The electrodes 15 being located on opposite sides of the vertical center of the furnace and preferably somewhat near the side walls of the furnace enable reflected heat from arcs formed between the corresponding electrodes 7 and 15 to be applied over the material to be melted at the sides of the central portion of such material. By placing the electrodes 15 at one side of the path or plane of electrodes 7 the arc ifiay be formed be tween the latter electrodes while at the same time the electrodes 15 enter the material to heat the latter by :the passage of current therethrou h. The electrodes 15 are shown 105 y water jackets 16 and suitable.

protected I insulation, said electrodes being shown connected with rods 17 provided with racks 1 8 engaged b i pinionsv 19 for operating the elec trodes.

or convenience 1n operatmg the I electrodes I have shown worms mesh ing with pinions 19 and carried by shafts 21 inclining downwardly and provided with operating wheels 22 located adjacent wheels 12 of shafts 12, so that the operator may readily operate said wheels as required, shafts 21 being provided with insulation 2?) at the bearings on supports 24, brackets 20 being insulated from the casing. Conductors 26 will be connected with the respective electrodes in any suitable manner, as by clips 27, and suitable switches will be arranged in the circuits so that current may be directed through the electrodes 7 for the horizontal arc, or through electrodes 15 for passage through the material to be melted, or through the pairs of electrodes 7, 15 at opposite sides of the furnace as required. The metal outlet 6 in the furnace may be closed in usual manner by a plug 29.

The metal to be treated, such as iron ore, mixed with any suitable flux and reducing agents, such as limestone, charcoal and tar, or other form of carbon, will be filled into the furnace to a suitable level, above the slag outlet 5. Electrodes 15 will be raised and current passed to flow through electrodes 7 tov produce a substantially horizontal are over the material, and by the form of the furnace shown the reflected heat from the arc will be caused to melt the material at the upper portion producing slag thereon. When the metal is sufiiciently melted by the reflected heat from the arc the electrodes 7 are withdrawn, (as indicated at the left in Fig. 1) and then the electrodes 15 will be lowered into the slag as far as desired, and the current then passed through electrodes 15 and the slag, whereby the material will be melted and the slag drawn off as required.

In case the material at one or both sides of the furnace cools off or is not sufficiently melted the electrodes 7 and 15 at such side or sides of the furnace will be adjusted in such position as to produce an arc between them, and such are will serve to further melt such metal at the corresponding side-of the furnace, it being understood that the are between electrodes 7 and 15 at either or both sides of the furnace may be used as required.

.case the ore will be mixed with the proper amount of flux and carbonaceous material so proportioned that only enough is allowed for the reduction of the ore. The horizontal arc is first used, and then when a suitable trodes 15 when in contact therewith.

- some amount of slag is formed the electrodes 7 are withdrawn or the current cut off, the electrodes 15 are lowered into the slag, thereby reducing the amount of electric energy required, and toward the end of the operation, as when the material has been reduced to the desired extent, the electrodes 15 are or may be withdrawn from the ma terial and the horizontal electrodes are again used to produce reflected heat from the arc to refine the metal and keep the percentage of carbon to the amount required. Furthern'iore, my furnace is particularly adapted to treating ore containing titanium and vanadium, and by suitably regulating the quantity of limestone, sulfur and titanium can be slagged off and fine steel can be obtained, or if a hard tool steel is desired when treating titaniferous iron ores less limestone may be used, and by regu lating the quantity thereof any desired pro portion of titanium can be retained in the steel.

Malleable iron may be produced from iron ore by mixing with the ore the required quantity of carbon and fluxing material, which will be less than for making steel from such ore, and where pig iron is to be produced the carbonaceous matter will be supplied to the required amount. In either 9 case note will be taken of any carbon that would enter the mass from the vertical elec- Other ores or materials may be reduced by means of my improved furnace by the use of the reflected heat from the are from the horizontal electrodes 7 and the heat from the electric current passedthrough the molten ma terial through the vertical electrodes 15 that enter the melted mass.

My invention is, therefore, applicable to the reduction of highly refractory materials of various kinds by reason of the facility with which the top portion of the material may be melted by the reflected heat from the are, and the operation continued by the current passing through said melted material from the vertical electrodies, and by the further facility with which t e material at the sides of the furnace may be heated when required by either pair of electrodes 7 and 15, or by both pairs. My invention is also applicable to the treatment of ores high in sulfur from which mild steel low in sulfur may be obtained. By adding desired quantities of titaniferous iron ores or small amounts of titanium or titanium alloys large percentages of sulfur may be eliminated from sulfurous iron ores and a hi h grade tool steelobtained, the amount 0 titanium retained in the steel being varied by the' amount of limestone or suitable fluxes which are used in the charge.

I do not in this application claim the method herein set forth of reducing refractory material as that is the subject of a separate application for atent filed by me on July 15, 1909, Serial 0. 507,681.

Having now described my invention What I claim is:

1. An electric furnace comprising a chamber, substantially horizontally disposed electrodes therein, a pair of separate electrodes independent of the first named electrodes adapted to enter the material in the chamber, and means for operating said electrodes at will, the horizontal electrodes being arranged to produce an are above the material in the chamber.

2. An electric furnace comprising a chamber, electrodes therein arranged to produce an are above the material in the chamber, electrodes independent of the first named electrodes adapted to enter the material in the chamber, and means for operating said electrodes independently.

3. An electric furnace comprising a chamber, a pair of electrodes adapted to produce an are within said chamber, a separate pair of electrodes adapted to enter the material in said chamber, and means for individually operating said electrodes at will.

4. An electric furnace comprising a chamber, electrodes adapted to extend across the same, and electrodes adapted to extend into the chamber at an angle to the first named electrodes, one of the first and second named electrodes being arranged to produce an are between them, the second named electrodes being arranged to enter the material in said chamber to pass electric current through said material.

5. An electric furnace comprising a chamber, substantially horizontally disposed electrodes adapted to enter said chamber to produce an arc, and a pair of electrodes ar ranged at opposite sides of the center of the chamber and adapted to cross the path of the first named electrodes, whereby an arc may be produced between one of the first and second named electrodes and the second named electrodes may enter the material to pass electric current through the same.

6. An electric furnace comprising a chamber, a pair of substantially horizontally disposed electrodes adapted to enter the chamber, and a pair of substantially vertically disposed electrodes adapted to enter the chamber and respectively alined with the paths of the first named electrodes, whereby arcs may be produced between one of the first and second named electrodes at opposite sides of the furnace.

Signed at New York city, in the county of New York, and State of New York, this 2nd day of July, A. D. 1909.

JOHN W. EVANS.

Witnesses:

HAROOURT BULL, T. F. BOURNE. 

